A. Field This invention relates generally to marine equipment protective devices, and more particularly to a protective cover for propellers, transducers and other underwater components to protect against marine growth.
B. Description of Related Art Underwater components, particularly propellers and connected propeller shafts, transducers and the like, are susceptible to the development of marine growth when submerged in sea water. Such growth can include barnacles, sea grass, slime, etc. (collectively referred to as “marine growth”). Marine growth that attaches to propellers remains attached even when the propeller turns to propel the boat at typical cruising speeds. Marine growth can significantly reduce the efficiency of the boat's propulsion system. Accordingly, countermeasures to ameliorate marine growth attaching to propellers have been proposed.
These countermeasures can take a variety of forms. One is to hire a diver to scrub and clean the propeller at regular intervals, or in advance of a voyage. Another is to apply an antifouling paint to the propeller. The art has further developed a variety of protective devices that are designed to cover or protect marine propulsion apparatus while in the water. Such protective devices are described in the patent literature, and include Sloan, U.S. Pat. No. 3,220,374; Pearce, U.S. Pat. No. 3,587,508; Crepeau, U.S. Pat. No. 6,916,217; Morton, U.S. Pat. No. 6,152,064; and Borrelli, U.S. Pat. No. 6,190,220. Other patents of interest include Ojeda, U.S. Pat. No. 5,273,399; Newman, U.S. Pat. No. 4,826,461; Doelcher, U.S. Pat. No. 5,527,193 and Lobrovich, U.S. Pat. No. 7,244,154.
The present protective system of this disclosure is considered an improvement over the devices shown in these patents in that it is particularly suitable for propellers, transducers and other underwater components that are submerged substantially below the waterline (e.g., as in most medium and larger sailboats and power boats due the installation of inboard diesel or gas engines) yet can be readily released by the user/boat owner from above the water before their trip, without requiring a diver to release the protective system. The solutions proposed for example by the Sloan and Crepeau patents, cited above, are applicable to outdrives of inboard/outboard motors or outboards where the propeller itself is either able to be raised out of the water or otherwise is readily accessible. However, they are not suitable for propellers for inboard engines in which the propeller is typically several feet (or more) below the surface of the water. These designs, if adapted for such a propeller, would require a diver to disengage the cover from the propeller. None of the designs of the prior art address the problems of fouling of propellers of larger vessels in which the propeller is submerged substantially below the waterline, or provide an effective protective system for such a vessel which can be readily released by the user from a position on deck, without requiring the services of a diver.